EU directives do not come into effect until countries within the EU incorporate them into domestic law. In each EU country, a law or provision refers to the relevant EU directive and thus elevates it to the status of domestic law.

Standard met, requirement met – harmonised standards

Standards alone have no legal relevance. until they are published in the Official Journal of the EU or are referenced in domestic laws and provisions. Publication of these harmonised standards triggers "presumption of conformity". Users applying the standard can therefore assume that they are acting in compliance with the law and directives. The burden of proof has therefore been reversed in the event of a claim. If a harmonised standard refers to a standard that has not been harmonised, the latter can obtain a status comparable to that of harmonisation.